Route planning devices are well known in the field of navigational instruments. The method of route planning implemented by known prior art systems depends on the capabilities of system resources, such as processor speed and the amount and speed of memory. As increased system capability also increases system cost, the method of route planning implemented by a navigation device is a function of overall system cost.
One feature of increased system capability cost involves the labeling of thoroughfares with a best name, or a most well-known name. Thoroughfare names are either shielded or not shielded. A shielded thoroughfare name is one that appears on signs along thoroughfares inside of a symbol rather than merely being spelled out. Examples of shielded name includes US1, I270, or State 91. A non-shielded name is a name for a thoroughfare that is not typically displayed in a symbol on signs, such as “Jeff Davis Highway” or “Jack Nicklaus Freeway.” Some thoroughfares have multiple names, some of which may be shielded and some of which may be non-shielded name, for example, “Jeff Davis Highway” in Virginia is a non-shielded name for the same thoroughfare whose shielded name is “US1.”
In general, thoroughfares are better known by their non-shielded name, except for interstate thoroughfares. For example, highway US1 is more well known by the non-shielded name of “Jeff Davis Highway.” In contrast, the I635 interstate beltway around Kansas City, Kans. is not very well-known by it's non-shielded name of the “Harry S. Darby” freeway.
Furthermore, conventional cartographic displays in navigational instruments frequently do not display the well-known non-shielded name of a thoroughfare. For example, conventional systems display the name “US1” on the display as a label for the thoroughfare that is better-known as the “Jeff Davis Highway.”
The frequent use of less-than-well-known thoroughfare names creates problems for the users of the cartographic data from navigation devices. Thoroughfare signs more frequently than not, identify thoroughfares using the better-known names of the thoroughfares. As a result, the names on the thoroughfare signs can be different than the name provided by the navigation device. When the names are different, the user may not correctly identify the thoroughfare while in route, and may travel past, or miss the intended course of navigation.
Additionally, thoroughfare names often have a suffix, such as “business” or “alternate.” For example, “I-44 business” in Rolla, Mo., designates a portion or spur of I-44 that services a business district of a city that is also known by the non-shielded name of “US63.”. An exception to the above rule in which interstates are most well-known by the shielded name is that interstates with a suffix are better known by their non-shielded name. Therefore, “I-44 business” is better-known as “US63.”
In summary, conventional systems often communicate a label to a navigational device with is a lesser-known name, or a nearly unknown name. Furthermore, conventional systems do not necessarily label a thoroughfare on a cartographic display of a navigational device with a better-known, or the best-known, name of the thoroughfare. Therefore, there exists a need for systems, methods, data structures, and apparatus adapted to communicate a label of a thoroughfare through an output of a navigational device with a better-known name, a well-known name, or the best-known name, of the thoroughfare.